First, her father died, and her mother was diagnosed with Alzheimer's. Then, without warning, her husband died of an aneurism.

''I just took to alcohol,'' she says. ''I didn't even really like it, I don't think. It was just to numb the pain and get out of the reality.''

And so it was for the next two decades of Isabella's life. Until that catastrophic string of events, she had been a social drinker. Then began a dark, double life of finding refuge in the booze, punctuated by episodes of getting on top of things.

''It's 20 years of like a revolving door,'' says the grandmother of four, whose experience is typical of an emerging crisis among older people who are turning to substance abuse in growing numbers.

''I'm in AA, I'm not drinking, something goes wrong and I start drinking again,'' Isabella says. ''But I know from going to AA that you can't be cured as such. But you can definitely live your life free of alcohol.''

There is mounting evidence that many older Australians are drinking at hazardous levels. The November conference of the Australian Professional Society on Alcohol and other Drugs heard of a University of Melbourne survey that found 7 per cent of 400 people over 60 were binge drinking weekly.

Another study by the University of NSW that looked at 65-year-olds presenting to aged care revealed in the preliminary data that one fifth had alcohol or substance abuse problems.

Not only is it a case of dealing with the known - alcohol and prescription drugs including benzodiaszepines - there is murky issue of illicit drugs, and taking those problems into old age.

In the case of people who inject or who are on methadone programs, we are seeing an increase in their median age in line with the broader ageing of the population.

This issue was identified in the December bulletin of the Illicit Drug Reporting System, from the University of NSW. It cited a recent US study that estimated that substance abuse disorders among adults 50 or older would double due to the boomers ageing. This was likely to be mirrored in other countries around the world. And boomers have a much higher rate of illicit drug use compared to previous generations.

''Aged care and geriatric medicine may be about to confront treatment challenges not see on this scale before,'' the bulletin warns.

Lucy Burns, the bulletin's co-author, says that while we are attuned to the increase in the health needs of Boomers, there had not been enough thought given to what it means for sub-groups such as people who inject drugs.

For example, people who inject drugs age earlier. ''The chronic diseases you might anticipate in the general population that might occur in the fifties will actually start to occur in the 40s in people who inject drugs,'' he says. ''So I don't think we do have that in our scope just at the moment.''

An insight into the world of the ageing drug users came in a 2010 discussion paper by the Australian Injecting and Illicit Drug Users League.

Stressing it was hard to accurately estimate numbers, the paper said there may be as many 30,000 regular opioid users aged 40 and over, and up to 80,000 infrequent or non-dependent users.

Users interviewed for the survey reported a greater degree of discrimination than younger people who injected drugs.

''It would seem that older injecting drug users are considered beyond help and redemption due to their advanced age,'' the paper said. ''As a result, they are judged more harshly than their younger counterparts who, according to popular thinking, may yet 'see the light' and move away from illicit drug use.''

A key issues emerging is the need for age-appropriate treatment, so that a 65-year-old doesn't find themselves next to an 18-year-old.

Isabella (whose name has been changed) owes her life - literally - to an innovative service , Older Wiser Lifestyle (OWL), which is working with older people with substance abuse problems.

An OWL psychologist was due to visit Isabella's home. ''The night before, I'd taken all sorts of pills and things, because I thought that it was easier if I wasn't here,'' she says.

The psychologist took her to hospital where she was admitted to the psych ward. It was a jolting experience. ''It was the most frightening thing I've ever been through,'' Isabella says.

Since then, things have looked up. Her daughter has become involved with sessions from counsellors, which has helped understanding that Isabella's abuse problems are a disease, not one of willpower.

The Victorian program runs the OWL program on a shoestring budget that allows for just 2.5 staff.

It's largely driven by the inspiration of Simon Ruth, who in 2007 travelled on a government fellowship to the US and Canada, countries streets ahead in the recognition and treatment substance abuse by older people.

''Since I've come back and I'm talking about it more, you'd be amazed at how many people who have an elderly relative, either a parent or an uncle or aunt, where they know they have a drug issue but they don't know how to talk to them about it,'' says Ruth, who is the director of complex service at Victoria's Peninsula Health network.

''We're not used to talking to our parents about their health issues and raising concerns with them. Parents are quite happy to push their kids into healthcare and argue with them about that. But we don't really know how to talk to our parents.''

In the US, Ruth says, they talk a lot about ''Granny's last vice: Granddad's dead, all the kids have left home, she's on her own, doesn't really have much in her life … so just let her have a couple of drinks, as long as it makes her happy.

''But the problem is that it's no longer making people happy and they're probably drinking too much, and it's causing other issues for them.''

Ruth's program is the only one of its kind in Australia. Yet it is clear that the kind of service it provides is barely scraping the surface of a problem that will only grow as the population ages.

The so-called ''silver tsunami'' is bringing with it health problems that include substance abuse. Predominantly, it is the abuse of alcohol, followed by prescription drugs. And as the baby boomers age, there is a belief illicit drug abuse will become a greater problem.

Historically, the focus of Australia's drug policy has been on younger people: the dangers of binge drinking, of party drugs.

But there is an existing, largely unseen problem of abuse among older people: the baby boomers and the pre-boomer generation.

''The ageing population is a hidden population,'' the executive officer of the Victorian Alcohol & Drug Association, Sam Biondo, says. ''They tend to be at home and out of view. They're not as obvious.''

A position paper by the association sets out the extent of the imminent crisis. The starting point is Australian Bureau of Statistic forecasts that the proportion of people aged over 65 will rise from about 13.5 per cent to about 25 per cent in the middle of the century.

''In the large part, substance misuse issues for the older population are pervasive yet silent, as many of the symptoms and harms are being subsumed and attributed to the normal ageing process,'' the paper says. It identifies an ''urgent need'' to bolster alcohol and other drug services to deal with the problem.

A reluctance to ask for help can be pervasive. Isabella recalls being brought up with a more stoic approach.

''If you do have a problem, you think, 'oh well, I better get on with it'. Nobody else is interested.'' But as she knows now, ''there are professional people so willing and able to help.''

Identifying the problem in the first place can be its own challenge. Jess Frederiksen was 60 before he realised that his depression was linked to his drinking.

''I've been living with depression most of my life, and I have been hiding in alcohol,'' he says.

Jess grew up in Denmark, where, he says, there is a drinking culture with ''a drink for any event''.

His father worked in a liquor shop, and they were close to the owners. Alcohol was always available.

At 12, he began drinking at home, with the occasional beer with the family in the evening. ''Then it just escalated to a point where I just got myself blind again and again, never really realising why.''

He came to Australia in 1983, and lived what on the surface what was a normal life. Married in 1985, the father to two children. (The marriage ended 15 years later.)

He also had no problem holding down jobs and was at one point self-employed. ''I was able to function, and never realised that I had a problem,'' he says.

Then came the program at Peninsula Health. He's got his drinking under control, ''not to the extent the doctors would like to see, but certainly to the extent that I'm happy with that.''

He has also rekindled a love in music, and has formed a band covering classic rock, called Vengeance.

He's also co-facilitating a SMART Recovery group, where people with addictions try to help each other.

One of the main things he has learned is that there is always a reason why people drink or use drugs to excess.

''If you don't deal with those problems, you are just likely to go on hiding in a bottle until day you die. There's really a great need for the kind of help that I've had.''